why do humans need to eat many different kind of foods to get their vitamins etc but large animals like cows only need grass to survive?

Question

why do humans need to eat many different kind of foods to get their vitamins etc but large animals like cows only need grass to survive?

In: Biology

Answer 1

Part of it is they’re bulk feeders. Cows will eat 20+ pounds of food a day, up to nearly 40 lbs for meat cows being fed for fast weight gain. They spend a huge portion of their waking hours just eating, with an otherwise sedentary life.

From this enormous food intake they can extract a decent quantity of nutrients that are relatively scarce in their diet. For more complex nutrients they basically carry around a biological factory in their gut to process the vegetable matter into all the proteins they need from their diet.